In a greenhouse environment it is often desirable to disperse fluids through or remove fluids from a growing medium such as soil containing plants. The capability of dispersing fluids through the growing medium allows the roots of plants to be supplied with air, water or solutions containing fertilizer or insecticides etc. The capability of removing fluids from a growing medium allows water saturated soil to be drained as required.
U.S. Pat. No. 2,022,398 (Beyer) discloses a plurality of panel members having parallel conduits extending between opposite edges thereof. The panel members are made of a heavy, porous material, namely burnt clay, which absorbs moisture and thus can be used to drain moisture from a growing medium. Because the material is porous, it would be difficult to control gas or liquid flow.
U.S. Pat. No. 4,309,843 (Kayto) discloses a plant cultivation device comprised of a corrugated plate having drainage holes positioned within parallel grooves therein. The corrugated plate rests on hollow concrete blocks arranged similar to drain tiles which carry away water seeping through the drainage holes. Sand between the blocks also helps to carry away water. This device would appear not to allow soil to be watered due to the sand between the concrete blocks and due to the lack of means for supplying water to the device.
U.S. Pat. No. 2,524,246 (Young) discloses a greenhouse bench bed having a corrugated aluminum bottom provided with perforations to drain excess water. The water drains directly below the bed and onto the ground. This device would appear to be incapable of introducing water to the bed through the perforations.
U.S. Pat. No. 3,118,249 (Bard) discloses a mushroom tray having a bottom sheet provided with a plurality of perforations. The perforations permit passive flow of air into the growing medium carried on the sheet. Presumably, these perforations may also be used to drain excess water. The device would appear to have no means for conducting away drainage water from the perforations and would appear to be incapable of introducing water through the perforations to the growing medium.
It is common for undesirable gases or liquids to be generated in municipal garbage dumps, industrial waste disposal sites etc. Such gases or liquids are commonly flammable, obnoxious smelling, toxic, etc. and the disposal of such gases or liquids has, in the past, been costly and often relatively inefficient. Gases generated in garbage dumps tend to collect in pockets, and/or leak through porous material to atmosphere, commonly producing foul smells, with a risk of explosions as the gases are commonly flammable. It is well known to provide a matrix of vertical stand pipes inserted into the material so as to collect the gases, and to permit safe burning of such gases. The cost of installing the matrix of vertical stand pipes is high and cost considerations dictate that there will be areas without adequate ventilation, with a consequent risk of excessive build up of gases and a high risk of explosion. Also, liquids leaching away from such material have, in the past, been drained by perforated drain tile or pipes buried in the material. Again, due to cost considerations, the pipes are disposed in a matrix and many areas of the dump are not adequately drained. This results in excessive build up of toxic liquids, which have been known to leach into ground water and contaminate water supplies, and adjacent land used for other purposes.
To the inventor's knowledge, the installation of water drainage or supply means to growing media in greenhouse applications, and the removal of undesirable gases or liquids from garbage dumps requires different types of apparatus which, in some applications, can be costly to install, and does not always perform adequately. It is desirable to provide a low cost, versatile device which can be used for either application above, and has sufficient versatility to accommodate the broad requirements of this wide range of applications.